Tubular tension support lines known as cable stays provide the upward support for a bridge that extends beyond the distance that can be self-supported by a horizontal structure. The cable stays can deteriorate or develop physical flaws over time and must be visually inspected periodically. The vertical structure that supports the cable stays is called a pier and the connection between the cable stay and the pier is called the anchor point.
The anchor point and cable stay can pull away from the pier and thus requires periodic inspections. The cable stays are typically five to eight inches in diameter. The cable stays are constructed as diagonal mounted cables that connect the vertical support pier to the horizontal deck. The cable stays have steel tendons inside and are filled with a cement mixture known as grout or some other chemical or material that can protect the internal steel. The condition of the exterior of the cable stays can indicate a more serious flaw and is one of the focuses of the inspection.
One existing means of inspection involves a person in a bucket truck or a person climbing up the cable stay and visually inspecting it. While this is slow and tedious, it also can lead to missed flaws and is dangerous to the inspector. Visual inspection from the ground by binoculars or telescope can also have the limitation of the angle and not being able to view the top or opposite side of the cable.
According a need exists for a system to inspect cables stays and the anchor pier connections completely and inexpensively that can be used on multiple types of bridges and cable stays, that is easy to transport between bridges and cables stays, and can provide complete inspection coverage of the cable stays and the cable stay anchor pier connections.